Check Engine and severe judder at idle
- Thread starter PJR
- Start date
PJR said:
My approach would be to swap the coil from cylinder #4 to e.g. Cylinder #3.
Clear codes, drive car.
If cylinder #3 comes up on the next read of the codes then its a coil.
Buy a new coil and a spark plug.
Swap out the coil. Clear the codes.
See if the problem recurs.
If the coil change fixes the problem, then check the date on the old one and decide if you can replace the rest depending on costs.
If the problem did not swap to cylinder 3 then change the spark plug on #4.
Repeat.
If it does recur then it is worth checking the wiring to the O2 sensor, if that seems OK then change the O2 sensor.
More than likely it's either a coil or spark plug not firing properly causing a too rich mixture hence the O2 sensor code.
If the spark plug was the cause then replace all plugs.
Where I am based, a plug is €20 coil is €40.
€60 for both x 6 = €360.
PJR said:
Compatible is fine. Usually Bosch or NGK.
BMW anyway uses either of those two. Generally specifies Bosch and/or NGK as the alternative.
These are service parts, so compatible is fine.
There are other brands out there but i've always stuck with these on my BMW's or Saab or Volvo (or Denso or Champions on other cars).
A long 14mm socket is what you need if you have it.
Ideally though a 14mm spark plug socket is best as it has a bit of rubber in it that grabs onto the spark plug and prevents it from falling.
Cheap enough even from halfords:
https://www.halfords.com/tools/hand-tools/sockets-and-accessories/halfords-professional-spark-plug-socket-228426.html
The other thing to consider is that some spark plugs have a 12 sided edge. So if your socket is not 12 sided it may not grip.
BTW, i'm saying 14mm because those fit my plugs on the 23i. Double check the plugs for your 28i. They should mention the socket size in the product description.
As an aside, if you haven't changed spark plugs before then ensure that you don't drop them before installing. In the past we used to have to "gap" spark plugs with a feeler gauge. These days they are pre-gapped.
However, if you drop them or knock the bottom electrode end it can become out of alignment and not sparking properly or sufficiently.
So don't do that.
It looks like you can get 4x coils & 4x plugs (Bosch) for a 28i for £140 from Euro Car Parts.
That's seriously good going IMO.
You will need a special 14mm spark plug spanner for these N20 engines….
I bought this baby..
https://www.amazon.co.uk/Toolwiz-Magnetic-Swivel-Spark-Socket/dp/B08FRH2MDN/ref=asc_df_B08FRH2MDN/?tag=googshopuk-21&linkCode=df0&hvadid=463110531023&hvpos=&hvnetw=g&hvrand=7218137003626334220&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006938&hvtargid=pla-1016164999397&psc=1
FWIW you need a decent swivel headed unit , number 4 cylinder is a bitch to get to…
Plus you need a decent torque wrench…
Not wishing to out you off but you have to be very careful not to cross thread these.
Coil wise I’d replace all 4, once one goes the rest are not long for this world..Bosch n NGK are both good.
Also when removing the plastic engine cover BE VERY CAREFUL…
There are two very small pipes that are push fitted on the underneath of the middle left hand side..
The turbo vacuum reservoir is moulded into the cover and the two pipes from the vacuum pump system and to the turbo are there.
The plastic barbs they push on are plastic, moulded in, non repairable and very fragile..especially with age..
I’d look at a YouTube video to get a good briefing
This is a good one..different chassis but irrelevant to the task in hand..
https://blog.fcpeuro.com/how-to-replace-bmw-f30-spark-plugs-ignition-coils-bmw-n20-n26-engine
I bought this baby..
https://www.amazon.co.uk/Toolwiz-Magnetic-Swivel-Spark-Socket/dp/B08FRH2MDN/ref=asc_df_B08FRH2MDN/?tag=googshopuk-21&linkCode=df0&hvadid=463110531023&hvpos=&hvnetw=g&hvrand=7218137003626334220&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006938&hvtargid=pla-1016164999397&psc=1
FWIW you need a decent swivel headed unit , number 4 cylinder is a bitch to get to…
Plus you need a decent torque wrench…
Not wishing to out you off but you have to be very careful not to cross thread these.
Coil wise I’d replace all 4, once one goes the rest are not long for this world..Bosch n NGK are both good.
Also when removing the plastic engine cover BE VERY CAREFUL…
There are two very small pipes that are push fitted on the underneath of the middle left hand side..
The turbo vacuum reservoir is moulded into the cover and the two pipes from the vacuum pump system and to the turbo are there.
The plastic barbs they push on are plastic, moulded in, non repairable and very fragile..especially with age..
I’d look at a YouTube video to get a good briefing
This is a good one..different chassis but irrelevant to the task in hand..
https://blog.fcpeuro.com/how-to-replace-bmw-f30-spark-plugs-ignition-coils-bmw-n20-n26-engine
PJR said:
As B21 above has said, there are other considerations.
He is more familiar with your particular engine and the intricacies thereof. Pay attention to what he said about the engine cover removal as i have not encountered that before on my vehicles.
But there are some generics.
Here is a running update.
Requirements:
1) Torx Bit - to remove engine cover - T30 or T27 (will update later)
2) 14mm Spark Plug Socket - Not required if you get B21's suggestion above
3) Long Socket Extension - Not required if you get B21's suggestion above
4) Socket Wrench - standard part of any toolbox
5) Torque Wrench
6) Spark Plugs
7) Code reader & reset tool
8) Penetrant Spray
9) Screwdriver - helps to insert into hole in coil cap to pull it up & out
Steps:
1) Remove engine cover by removing the 4 or more Torx Screws on the cover.
2) Pull up on the latch on the ignition coil to unseat the electrical connector and pull out the connector
3) Insert the screwdriver into the hole in the ignition coil latch and pull up to remove the coil
4) Insert the Spark Plug Socket into the cylinder tube and open the plug by turning the wrench anti-clockwise
5) DO NOT force it - if it seems too resistant then spray in some penetrant spary and wait a few hours before trying again.
6) Insert the new Spark Plug into the Spark Plug Socket and insert it into it's place in the cylinder tube.
7) Hand tighten by turning the extension only (clockwise) and NOT the wrench.
8) Ensure that it turns easily with no resistance and you do not want to cross thread it.
9) Tighten by hand until it goes no further.
10) Insert the socket wrench into the top of the socket/extension and tighten until a slight amount of resistance is felt. Do not over-tighten!
11) If you have a torque wrench, then set it to the recommended value for your spark plug and tighten accordingly. If you don't have one, then perhaps nicely ask a local mechanic at a later stage.
12) Insert the (NEW) ignition coil and electrical connector and latch shut ensuring connector is fully seated and coil has been fully pressed down.
13) Clear the codes on the car
14) Test by starting & driving the car
Having changed the plugs and/or coils in a car one may find it still sounds like crap or even worse than before. Just ensure that all coils are properly seated / pressed down and all electrical connectors are fully seated.
I'm not sure what you are saying.
Except to say that the roundabouts are still the same direction in my part of Ireland since Brexit.
We still have right hand drive cars. We still have roundabouts to the right. Nothing has changed.
Come on over. It's easier than France.
We don't require ANY changes to the headlamps or even to anything else.
100 years later, it's a really nice place!
Except to say that the roundabouts are still the same direction in my part of Ireland since Brexit.
We still have right hand drive cars. We still have roundabouts to the right. Nothing has changed.
Come on over. It's easier than France.
We don't require ANY changes to the headlamps or even to anything else.
100 years later, it's a really nice place!
Smartbear said:wanderer said:
You don’t need to undo any screws to remove the plastic engine cover, they just pull off
Rob
Yes pondered the existence of these torx screws..the cover has a tab at the back so lift at the front then pull diagonally forward and up..other wise you can break the back tab..of course removing turbo related pipes first
Touching wood, and counting no chickens... but the job seems to be done and all appears to be working fine after a quick spin up and down the local bypass.
Could not get one of the hoses removed from the engine cover, but managed to work around that ok.
The old plugs all came out pretty easily and new ones seemed to go in fine, though when I torqued them from hand tight with the wrench they seemed to hit torque immediately, unless I miss understood the noise coming from the wrench.
The OBD code reader would not however clear the misfire code.
I was expecting the old coils to have been the original ones (2012 car with under 80,000 miles) but they didn’t have any branding on them at all and did not look like the Bosch ones I’ve now installed.
Thanks again everyone for fantastic advice and encouragement... as someone who is a pretty serious klutz with mechanical things it was a bit of a nerve wracking process, but fingers crossed it’s a job done!
Could not get one of the hoses removed from the engine cover, but managed to work around that ok.
The old plugs all came out pretty easily and new ones seemed to go in fine, though when I torqued them from hand tight with the wrench they seemed to hit torque immediately, unless I miss understood the noise coming from the wrench.
The OBD code reader would not however clear the misfire code.
I was expecting the old coils to have been the original ones (2012 car with under 80,000 miles) but they didn’t have any branding on them at all and did not look like the Bosch ones I’ve now installed.
Thanks again everyone for fantastic advice and encouragement... as someone who is a pretty serious klutz with mechanical things it was a bit of a nerve wracking process, but fingers crossed it’s a job done!
Without a decent code reader you are unlikely to understand what caused the fault …if it was a simple coil / plug fault then normally the engine check light out should reset on a restart..
I assume what you are saying is that the check engine light is off but the code remains in the DME and your cheap code reader can’t clear that code?
I assume what you are saying is that the check engine light is off but the code remains in the DME and your cheap code reader can’t clear that code?
PJR said:
You changed the coils & plugs and no more problem as experienced previously.
Car is driving as it should be. Great stuff!
Certain codes will survive a restart if not cleared manually. They become historical codes.
You never mentioned which code reader you purchased. It is entirely possible that it may not be able to clear codes or all codes.
However, drive more!
